Atlantic Tropical Weather Discussion (Text)

000
AXNT20 KNHC 191042
TWDAT
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
642 AM EDT Mon Mar 19 2018
Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.
Based on 0600 UTC surface analysis and satellite imagery through
1030 UTC.
...SPECIAL FEATURES...
Atlantic Gale Warning: Southerly flow will increase off northeast
Florida late tonight and Tue ahead of a cold front moving into
the region late Tue. SW to W winds will reach gale force north of
28N late Tue through Wed as the front moves east.
...MONSOON TROUGH/ITCZ...
The monsoon trough extends from the coast of Africa near 07N11.5W
to 05N20W. The intertropical convergence zone continues from that
point to 05N45W. A few showers are noted within 30 nm on either
side of the boundaries between 13W and 30W.
...DISCUSSION...
GULF OF MEXICO...
Weak ridging extends from southeast Florida to the north central
Gulf, supporting light to gentle southeast winds over most of the
region. Areas of fog and low stratus are evident this morning in
satellite imagery and surface observations across the northwest
Gulf and portions of the north central Gulf.
The ridge is shifting east ahead of a cold front that will move
off the Texas coast later today. The front will extend from the
Florida Big Bend area to Veracruz Mexico tonight, just as a
reinforcing push of cold air moves off the Texas coast. The
reinforcing front overtakes the first front late Tue, accompanied
by strong winds and building seas over the northern Gulf. The
merged front sweeps southeast of the Gulf by early Wed. Winds and
seas diminish across the Gulf through Thu as high pressure
follows the front across the northern Gulf.
CARIBBEAN SEA...
A pair of scatterometer passes from 03 UTC confirmed a large area
of fresh to strong trade winds off Colombia, and a smaller area
of strong winds south of the Bay Islands off central Honduras.
Seas are reaching 8 ft off Colombia, but are generally 4 to 6 ft
in the eastern and central Caribbean and tropical north Atlantic,
and 2 to 4 ft in the northwest Caribbean. No significant convection
is noted.
Building high pressure north of the region will support fresh to
locally strong trades across the south central Caribbean the
next several days, except increasing to near gale force along the
northwest coast of Colombia during the overnight hours. A cold
front will pass through the Yucatan Basin by early Wed, then
drift south and stall from the Windward Passage to central
Honduras Fri, followed by fresh northerly flow and seas building
to 7 ft.
Undersea volcano Kick em Jenny, north of Grenada near 12.18N
61.38W, is in a state of unrest. The government of Grenada
advises mariners to observe a 5 km or 3.1 nm exclusion zone
around Kick em Jenny. Please see www.nadma.gd for additional
information.
ATLANTIC OCEAN...
Please see Special Features section for information on the
developing gale warning in the Atlantic.
A weak cold front extending from near Bermuda to northeast
Florida will shift eastward and weaken through Tue. A few
thunderstorms are noted along the frontal boundary north of 29N
between 60W and 65W. Farther south, weak ridging is supporting
gentle breezes west of 60W, with 4 to 6 ft seas in open waters
east of 75W, due mainly to residual northerly swell.
The next cold front will move off the coast late Tue, associated
with a deep surface low moving off the mid-Atlantic coast. The
supporting upper trough will become negatively tilted as it
emerges off the coast. This will interact with the Gulf Stream to
support scattered thunderstorms Tue night off the northeast coast
of Florida. In addition to the gales, strong westerly winds and
seas ranging from 8 ft to as high as 17 ft will prevail north of
27N and west of 60W into Wed night.
Winds and seas will diminish Thu as the front reaches from
Bermuda to the Windward Passage, before stalling and weakening
through late week. A weaker front will move eastward north of 28N
Thu night into Fri.
Over the eastern Atlantic, 1025 mb high pressure is centered near
30N27W, supporting gentle to moderate NE to E winds over the
subtropics and moderate to fresh trades in the deep tropics. An
upper trough is noted along 28W north of 05N, supporting a few
small areas of modest convection along the monsoon trough and
ITCZ. Recent altimeter satellite passes indicate seas are still 8
to 12 ft north of 05N, likely in persistent long period NW swell.
For additional information please visit
http://www.hurricanes.gov/marine
$$
Christensen